viral and nematode diseases of banana

1. Viral and Nematode Diseases of Banana
University of Agricultural sciences,benagaluru
Submitted to,
Somasekhara sir
Dept of pathology
Submitted by,
Rashmi.A
ALB8202
3rd year c’section
B.sc (Hons) Agriculture
College of Agriculture
Pathology321(1+1)Assignment

2. Viral Diseases
• Banana mosaic
• Banana streak
• Banana bunchy top
• Banana bract Mosaic

3. Banana Mosaic/ Infectious Chlorosis
Etiology:
Cucumber mosaic virus
This virus is a member of the cucumovirus group and belongs to bromoviridae..
Primary spread :Virus particles through diseased suckers used for planting.
Secondary spread : Virus particles transmitted by banana black aphids, Aphis gossypi, A. maydi.
Cucumis sativus serves as a latent reservoir host.
Economic impact:
This disease is under domestic quarantine in India.
The movement of planting suckers from Gujarat and Maharashtra to other parts of the country is banned.
CMV causes great losses in vegetables, ornamentals and fruit crops

4. • Favourable conditions:
• Late and post monsoon period favours virus spread and symptom expression.
• Prevalence of infected reservoir host, Prevalence of vector.
Symptoms :
• Typical mosaic-like or discontinuous linear streaking in bands extending from margin to midrib
running parallel to veins (Mosaic).
• Chlorosis of newly emerged leaves (Infectious chlorosis).
• Deformation and curling of leaves.
• Necrosis of emerging cigar leaves in the unfurled leaf lamina.
• Internal tissue of pseudostem turns necrosis.

5. Diagnostic Symptoms

6. Management Practices
• Identify the infected plants based on their external symptoms and remove along with the
underground corm.
• Use of virus indexed certified tissue culture plants.
• Plant only disease-free suckers.
• Keep the field free from weeds and don’t cultivate cucumber mosaic virus susceptible crops
as inter crop.
• Spray systemic insecticides to control the vectors which help in preventing the spread of the
disease.
• Growing Resistant varieties Musa bulbisiana.

7. Banana streak
• Banana streak virus (BSV) is an important disease of Musa and affecting the productivity of both bananas and plantains.
• Reported in nearly all countries where this crop is grown including Mauritius, India and many countries of the African continent.
Symptoms:
• Chlorotic and necrotic streaks on leaves.[Chlorotic streaks become necrotic (blackish color)]
• Necrotic streaks on midrib and pseudostem petiole.
• Bunch choking, abortion of bunch and seediness in fingers.

8. Management practices:
• Use of virus indexed certified tissue culture plants.Plant only disease-free suckers.
• After harvest collect the infected plant and destroy.
• To avoid loss due to streak virus affected plants, apply 25-50 % more recommended
dose of fertilizers and 10kg FYM/ plant.

9. Banana Bract mosaic
Economic impact:
• First reported from Mindanao, Philippines in 1979.
• Recorded in Srilanka, India, Vietnam and Philippines • In India, this virus disease was first.
• reported in Kerala as Kokkan disease.
• Very rapidly spreading in all the banana growing states of India in the absence of regulation on the movement of suckers.
Etiology:
Banana bract mosaic virus (BBrMV)
BBrMV belongs to the genus Potyvirus in the family Polyviridae.
Primary Virus particles vertically spread through diseased suckers used for planting.
Secondary: Virus particles are transmitted by banana aphids, Aphis gossypii,
A. maydis and Rhopalosiphum maidis in non persistent manner.

10. • Symptoms:
• Presence of spindle shaped pinkish to reddish streaks on pseudostem, midrib, peduncle and bracts.
• Spindle shaped mosaic on the emerging leaf
• Typical mosaic and spindle dark reddish-brown mosaic streaks also appears on young suckers.
• In Nendran, the leaf orientation changes in such a way giving the appearance of ‘Travelers palm’ plant.
• Bunches with unusual either very long or very short peduncle, chocking of bunches, raised corky growth on
peduncle are also observed. Extended female phase after a short male phase has been observed.
• Management practices:
• Use of virus indexed certified tissue culture plants.
• Plant only disease-free suckers.
• removal and destruction of infected plants.
• To avoid loss due to bract mosaic affected plants,,
apply 25-50 % more recommended dose of fertilizers
and 10kg FYM/ plant.

11. Diagnostic symptoms
(BBrMV)

12. Bunchy top
Economic impact
First reported from Fiji in 1889 in Cavendish varieties,Around 1940, introduced into India from Srilanka through cyclone.
The virus is a domestic quarantine pest in India.
The movement of planting suckers from North East, Tamil Nadu, Karnataka and Kerala to other parts of the country is restricted.
Etiology
Banana bunchy top virus.
Primary: Virus particles through diseased suckers used for planting.
Secondary: Virus particles transmitted by banana black aphid, Pentalonia nigronervosa.
Colocasia esculenta serves as a latent reservoir host.
Favouravle condition
• Progressively increasing temperature from February onwards favours virus spread
• and symptom expression
• Prevalence of infected reservoir host(Canna, Heliconia, Strelitzia)
• Prevalence of aphid vector

13. Symptoms:
• Dark green streaks appear on midrib, petiole and veins of lamina.
• Marginal chlorosis in the leaf lamina resembles iron deficiency symptom
• Plants with the advance stage of infection show rosette appearance
with progressively shorter, narrow, brittle textured leaves giving rise to
the common name of ‘bunchy top’.

14. • The infected plant show dark green streaks on the tip of the bracts and the bracts tip of male bud is turn into leafy
green.
• In Grand Naine banana, the BBTD affected plants throw bunch with extremely long or very short peduncle.
Sometimes affected Grand Naine banana fingers appear like a non- Cavendish type fruit.
• .
Management practices
•Use of virus indexed certified tissue culture plants
•Plant only disease-free suckers, Spray systemic insecticides to control the vectors
W. Which help in Preventing the spread of the disease
• Adoption of strict quarantine measures
•Use of only certified banana suckers or tissue culture plants for planting
• Periodical monitoring and rouging of infected plants with all suckers in the mat
y by rouging or killing by injecting herbicide, 2,4-D

15. Nematode diseases
• Burrowing nematode
(Radopholus similis)
• Root-lesion nematode,
(Pratylenchus coffeae)
• Root-knot nematode,
(Meloidogyne spp)
• Spiral nematode,
(Helicotylenchus multicinctus)

16. Banana Burrowing nematode (Radopholus
similis)
• First reported from Fiji by Cobb in 1893 Fist reported in India byt Nair 1966 in Kerala
• Other names are Black head, decline, root rot, toppling over.
• Distribution: Fiji, Australia, India Newseland.
Symptoms:
• Infested plants exhibit general decline, stunting, premature defoliation
and produce small bunches and fruits.
• Symptoms on roots and corms exhibit sunken lesions on young roots
and on older roots and surface cracks appear.

17. • Extensive reddish-brown lesions appear in the cortex when cut longitudinally. They cause decay and
death of roots.
• Affected plant topple over easily during wet and windy weather because of poor anchorage
Management practices
• PRING AND PRALINAGE Removal of infected tissues
• With surrounding healthy tissue and dipping the suckers
• In cow dung slurry
• Heat therapy-hot water 55°c for 10 min
• Crop rotation with sugarcane
• Soil application of carbofuran, cartop hydrochloride
• Resistant var Pisang lilin
• Susceptiple cavendis, robusta
• Soil application of carbofuran along with neem cakes.

18. Diagnostic symptoms of Burrowing
nematode

19. Root-lesion nematode,(Pratylenchus
coffeae)
Symptoms:
• Damaged roots exhibit extensive black /purple necrotic lesions
• on root surface.
• Longitudinal sectioning of infected root exhibits necrotic lesions
• on cortical regionwith healthy vascular region.

20. • Necrotic lesions are also found on the corm.
• Damage on the corm and roots leads to stunting,
• decreased bunch weight, lengthening of the production cycle
• and toppling of plants.

21. Root-knot nematode, Meloidogyne spp
• The root-knot nematodes attacking many crops in tropical countries are also found to attack banana
and plantain roots wherever this crop is grown.
• Among the six identified species, Meloidogyne incognita and M. javanica are the most common and
widely distributed in banana growing regions.
• The root-knot nematode, M. incognita is the predominant species and highly pathogenic to Poovan
banana. The nematode causes nearly 31 per cent yield loss in Poovan banana in Tamil Nadu.
Symptoms:
• Infested plants are stunted in growth with pale yellow narrow leaves exhibiting
bushy appearance.
• Under severe infection, leaf margin dries. The plants bear smaller bunches
with reduced number of hands with smaller fruits.
• Profuse galling on primary and secondary roots with
egg masses are seen when the roots are cut longitudinally.

22. • The root tip growths cease, and excessive branching of new roots proliferate just above
the infected tissues.
• Infected plants may have a much lower number of secondary and tertiary roots.

23. Spiral nematode, (Helicotylenchus
multicinctus)
Symptoms:
• Spiral nematodes cause superficial lesion
on the surface of the roots.
• It causes extensive root necrosis,
dieback and functional disturbance eventually
leading to the death of the plant.

24. Integrated nematode management
• If nematode population is very high in the field, crop rotation with paddy, sugarcane,
green gram, sunn hemp or cotton is recommended to reduce the nematode population.
• Fallowing the land for three months after banana harvest and summer ploughing
effectively suppress the nematode population.
• Growing sunn hemp prior to planting banana and after flowering incorporate them into
the soil.
• Paring the corm surface by trimming away necrotic lesions and sucker dip treatment with
Nimbicidin or Juerken @ 15 ml / litre (1.5%) of water for 30 minutes.
• If tissue culture plants are used, apply 10g of carbofuran at planting and 20g / plant at
third and fifth months after planting.

25. • Apply neem cake @ 500g /plant at the time of planting and at four months after
planting with any one of the bio-control agents viz., Pseudomonas fluorescens /
Trichoderma viride / T. harzianum / Pochonia chlymydosporia / Purpureocillium
lilacinum @ 20 g/plant at planting and 3rd and 6th month after planting or apply
Carbofuran @ 30g/plant at the time of planting and at 3 months after planting.
• Grow marigold (Tagetes erecta & T. patula) as intercrop in banana.
• Banana cultivars Robusta, Grand Naine, Poovan, Rasthali, Ney Poovan, Red Banana,
Virupakshi and Nendran are susceptible.
• Banana varieties like Karpooravalli, Monthan, Nattupoovan, Kunnan, Pey kunnan,
Pedali moongil, and Pidi Monthan are tolerant.

26. Thank you